The masonry of the great house and tower type (pl. 11, _a_, _b_) varies
in excellence, not only in different examples but also in different
portions of the same building. Some of the walls contain some of the
best-constructed masonry north of Mexico; others (see pl. 6, _b_) are
crudely made. In the Great House of the Holly group, where the walls
show superior construction, the lowest courses of rock are larger than
those above, but in Hovenweep Castle small stones are found below those
of larger size; the Round Tower in McLean Basin shows small and large
stones introduced for ornamentation.
The ambitious constructors of several towers have built the foundations
of these towers on bowlders sloping at a considerable angle, and it
is a source of wonder that these walls have stood for so many years
without sliding from their bases. Although so well constructed in many
instances, the courses were weak from their want of binding to the
remaining wall. As a consequence many corners have fallen, leaving
the remaining walls intact. The builders often failed to tie in the
partitions to the outer walls, by which failure they lost a brace and
have sprung away from their attachment.
In a general way we may recognize masonry of two varieties.
1. That in which horizontal courses are obscure or absent. This has
resulted from the use of stones of different sizes, the intervals
between which are filled in with masses of adobe. These stones are
little fashioned, or dressed only on one side, that forming the face of
the wall.
2. That constructed of horizontal courses, constituting by far the
larger number of these buildings. Each course of this masonry is made
of well-dressed stones, carefully pecked, and of the same size. In this
horizontal masonry the thickness of stones used may vary in different
courses (pl. 11, _b_). They may be alternately narrow or thick, or
layers of thick stones may be separated by one or more layers of
tabular or thin stones. This method of alternation may be so regular
as to please the eye and thus become decorative, a mode of decoration
that reached a high development in the Chaco Ruins. The stones in the
horizontal style of masonry are equal in size throughout the whole
building in some cases, and show not only care in choice of stones but
also in dressing them to the same regulation size. In these cases the
joints fit so accurately that chinking has not been found necessary and
a minimum use of adobe was required.
The inner walls of kivas are much better constructed than the outer
walls of the same or of the walls about them. The masonry here is
regular horizontal. The sides, lintels, and thresholds of doorways
are among the finest examples of construction. With the exception of
walls sheltered by overhanging cliffs, the plastering has completely
disappeared, but there is no reason to doubt that the interiors of all
the great houses and towers were formerly plastered.
It is instructive to compare the masonry of the great houses and
towers of the Mancos with that of the towers in Hill Canyon (pl. 11,
_c_) in Utah, the most northern extension of these two types. In Eight
Mile Ruin, one of the largest of these buildings in Hill Canyon, we
have a circular tower with annexed great houses, all constructed of
well-dressed stones, the masonry in the walls showing on one side of
the tower. No excavations, however, have yet been undertaken in Hill
Canyon Ruins, and it is not known whether the unit type of kiva is
found there, but the combination of great houses and towers is evident
from the ground plans elsewhere published.[41]
The feature of the towers in Hill Canyon is the clustering into groups,
somewhat recalling the condition in Cannonball Ruin, where, however,
they are united. In the Eight Mile Ruin one of the towers is separated
from the remaining houses.
Several towers have accompanying circular depressions with surrounding
mounds. This association can well be seen in Holmes Tower on the
Mancos Canyon and in Davis Tower and one or two others on the Yellow
Jacket. These depressions, sometimes called reservoirs, have never been
excavated, but from what is known of rooms accompanying towers in the
western section of Hovenweep Castle it may be that they indicate kivas.
Some towers have no sunken area in the immediate vicinity, especially
those mounted on rocky points or perched on bowlders. At Cannonball
Ruin there are several kivas side by side in one section and towering
above them is a massive walled tower and other rooms.